【作者】 李志强；

【导师】 罗应立；

【作者基本信息】 华北电力大学（北京） ， 电机与电器， 2009， 博士

【摘要】 本文在精确考虑铁磁材料非线性及永磁磁路复杂结构的条件下研究自起动稀土永磁电机的动态过程。首先研究了同步电机动态分析的共性问题,即局部电磁力、电磁转矩计算与场-路-运动直接耦合求解问题,进而对稀土永磁电机起动、失步、断相、重合闸等动态过程进行时步有限元分析和实验研究。主要创新性成果如下:1.在同步电机动态分析共性问题研究方面,推导了计及铁磁介质饱和时的同步电机等效节点力计算公式,建立了用于永磁电机局部电磁力分析的电磁力密度计算模型;提出了适用于电励磁和永磁同步电机的场-路耦合稳态有限元分析法,并建立了动态过程分析的场-路-运动直接耦合时步有限元新模型。2.通过大量的计算分析和实验对比,揭示了永磁电机堵转电流不对称以及堵转转矩随堵转位置波动的根本原因,以及初始起动条件、线路阻抗等多个因素对起动性能的影响。3.通过对永磁电机失步、重合闸以及断相等非正常动态过程的时步有限元分析,提出快速准确计算失步转矩的新方法,以及减小重合闸冲击电流与冲击转矩的新判据;揭示了断相前后定转子电流、损耗和转矩的变化幅度与负荷大小之间的关系。4.提出了一种经济实用的瞬态转速转矩实时测量方案,实现了瞬时机械量与电气量的同步采集,参加设计并研制了永磁电机动态性能综合测试平台。更多还原

【Abstract】 Dynamic process of line-start rare-earth permanent magnet motors were researched in this dissertation with nonlinear characteristics of ferromagnetic material and complex structure of permanent magnetic circuit precisely considered.Firstly,the common problems such as local electromagnetic force,electromagnetic torque computation,and field-circuit-motion directly coupled solution problems were studied.And then dynamic process including starting,losing step,reclosing and open-phase operations were analyzed with tine-stepping finite element method(FEM) and field experiments.The main innovations are summarized as follows:1.In the study on common problems of synchronous motors’ dynamic analysis,an equivalent nodal force formula considering saturation of ferromagnetic material is derived,and thus a model is founded for electromagnetic force density calculation in analyzing local magnetic force of permanent magnet motor;a field-circuit coupled stationary finite element method,suitable for electrical excitation and permanent magnet motors,is proposed,and a novel time-stepping FEM model with field-circuit-motion direct coupled is established for the analysis of dynamic process.2.Based on a great deal of computations and experiments,the reasons for asymmetry of locked-rotor currents and for locked torque’s fluctuation due to the change of locking position are revealed,as well as the impacts of the initial starting condition and line impedance on starting performance.3.Through the time-stepping FEM research of abnormal transient processes such as losing step,reclosing and open-phase operation,a new efficient and accurate calculation method for pull-out torque and a practical reclosing criterion to reduce inrush current and torque are proposed;the relationship between load and the amplitude change of rotor current,the loss and torque in open-phase operation is revealed as well.4.An economical and practical program for real-time measurement of transient speed and torque is proposed,and synchronous acquisition of mechanical and electric quantities is thus achieved.Moreover,an integrated test platform for dynamic performance of permanent magnet motor is designed and developed.更多还原